Packaging method and apparatus

ABSTRACT

Method and apparatus for stacking and packing frangible generally cylindrical articles such as doughnuts includes expelling successive such articles from the end of a conveyor means so that the articles fall successively into hollow, generally vertical tubes. Arms extending inside the tubes are gradually lowered as successive articles fall into the tubes so that all articles fall approximately the same distance. When a predetermined number of articles form a stack within each of the tubes, the arms are further lowered to lower the formed stacks below the tubes. The arms are lowered through openings in a plate, leaving the stacks supported on the plate. A pusher plate is then reciprocated generally horizontally to push the stacks into a container, which is then righted and conveyed away.

United States Patent [1 1 Williams [451 July 17,1973

[73] Assignee: Scott Machine Development Corpo ration, Walton, NY.

[22] Filed: Feb. 16, 1971 [21] Appl. No.: 115,169

52 us. Cl 53/26, 53/162, 198/35 Primary Examiner-Robert L. Spruill Attorney-Richard G. Stephens [57] ABSTRACT Method and apparatus for stacking and packing frangible generally cylindrical articles such as doughnuts includes expelling successive such articles from the end of a conveyor means so that the articles fall successively into hollow, generally vertical tubes Arms ex tending inside the tubes are gradually lowered as successive articles fall into the tubes so that all articles fall approximately the same distance. When a predetermined number of articles form a stack within each of the tubes, the arms are further lowered to lower the formed stacks below the tubes. The arms are lowered through openings in a plate, leaving the stacks supported on the plate. A pusher plate is then reciprocated generally horizontally to push the stacks into a container, which is then righted and conveyed away.

10 Claims, 7 Drawing Figures PATENIEB JUL 1 mm SNEEI 1 (If a I N VENTOR.

THOMAS A. W|LL|AMS PATENTED JUL 3 7 I973 PATENTED JUL 1 '7 ma SHEET 3 0F 0 vm mm Q J v u i m Tom 8 248 l I [1} -65: b w N A QUE H MOE PACKAGING METHOD AND APPARATUS This invention relates to packaging machinery, and more particularly to improved method and apparatus capable of automatically stacking and packing predetermined numbers of articles, such as doughnuts, in a portable container such as a cardboard box. A wide need exists for apparatus which can automatically stack and package cylindrical articles of various types and articles which are merely generally cylindrical. If the hole through an ordinary doughnut is ignored, it will be appreciated that a doughnut has a generally cylindrical shape. So-called English muffins and various other bakery goods, such as some other muffins, cookies and rolls, are commonly formed with shapes at least roughly approximating a cylinder. A variety of stacking and packing techniques which are quite satisfactory for rectangular articles and articles of other shapes are not useful for stacking or packing articles having a generally cylindrical shape. Also, various stacking and packing techniques which may be useful in connection with durable articles are not useful in connection with frangible or delicate articles such as bakery goods because they tend to damage too many of the articles, unless in some cases very slow speeds of operation and small gripping forces are used.

It is particularly desirable in the case of food articles that they be packaged automatically by machine rather than manually, both because of labor costs and so that the articles will truly be untouched by human hands. Thus it is one object of the invention to provide improved methods and apparatus for stacking and packing generally cylindrical articles, and a more specific object of the invention is to provide improved method and apparatus for stacking and packinG delicate or frangible articles. It will become clear, however, as the description proceeds, that the method and apparatus of the invention are applicable as well to stacking and packing a variety of other articles.

Further objects of the invention are to provide stacking and packing method which involves only a few simple steps, and to provide stacking and packing apparatus which is simple and inexpensive to construct and reliable in operation.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.

' For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. I is a plan view of one form of the invention.

FIG. la is a side elevation view taken at lines Ia-]la in FIG. I.

FIG. Ib is a partial downward section view taken at lines Ibllh in FIG. In.

FIG. 2 is a schematic diagram illustrating one form of synchronizing unit which may be used to drive various portions of the device of FIGS. ll, Ia and lb.

FIG. 3 is a side elevation view generally similar to FIG. Ia but showing various modifications which may be made to the invention.

FIG. 4a is a plan view of a portion of an alternative form of the invention.

FIG. 4b is an elevation view taken at lines 4b4ib in FIG. 4a.

In the drawings, various brackets and common sup port structure has been omitted for sake of clarity and to afford clearer views of important elements of the invention.

Referring now to FIG. 1, input conveyor 20 represents a conveyor which travels leftwardly. Articles (such as doughnuts) to be packaged are placed on the right end of conveyor 20 ordinarily in random fashion, by means not shown. Conveyor 20 may comprise the conveyor ordinarily used in bakeries which conveys doughnuts away from a sugaring station, or any last sta tion at which the doughnuts are treated. Stationary side guide plates 22, 22 situated just above belt 211 of input conveyor 20 prevent the articles from falling off the sides of the belt, and center guide plates 23, 23 automatically separate the doughnuts into three separate rows as conveyor belt 211 is advanced.

With three articles situated at the exit end of belt 21, in the position of article D shown in FIG. Ia, further motion of the belt will be seen to push the three articles in approximate unison off the edge of plate 911. In FIG. Ia article D is shown in dashed lines in various successive positions as it falls from plate III. It should be noted that the article turns over degrees, or inverts, as it falls. As the center-of-gravity of the doughnut is pushed beyond the leftward edge of plate M, the right side of the doughnut is temporarily supported by the plate as the left side falls, thereby imparting a counterclockwise rotation to the doughnut as it partially falls and partially slides off of the edge of the plate 9i. Each of the three articles expelled at a given time from plate 9i flips over and lands in a respective hollow cylindrical guide tube, three such guide tubes being shown in FIG. I at 25, 26 and 27. The generally vertical guide tubes each include a slot along its length to allow platform arms 311-33 to extend inside the guide tubes and be lowered through the guide tubes. In FIG. I a portion of platform arm 32 has been cutaway to afford a clear view of slot 26a in guide tube 26. Two endless chains 51, 52, each carried on a pair of sprockets, are driven in unison by means to be described. A plurality of rigid bars 53a to 53f (FIG. Ia) extend horizontally between respective links on chains SI and 52, and three platform arms extend outwardly from each of the rigid bars. Thus as the chains are rotated, successive trios of platform arms pass downwardly through the guide tubes. The rigid bars and platform arms are spaced at equal intervals along the chains.

As a first trio of doughnuts are expelled by conveyor 2% off plate 911 to fall into guide tubes 25-27, the platform arms III--33 are positioned within their respective guide tubes near the tops of the tubes, in the position shown for arm 32a in FIG. Ia, and each doughnut descends within a guide tube until it rests on the shaped end of the platform arm situated within the guide tube. Arms 31-33 are lowered at such a speed as to be lowered an amount approximately equal to the thickness of a doughnut as conveyor 2% is advanced far enough to push three more doughnuts into the tops of the guide tubes. The distance which the conveyor is advanced during the time in which the arms are lowered that amount will be seen to be approximately equal to the outside diameter of a doughnut. The second three doughnuts similarly fall into the guide tubes and descend until they rest on top of the first three. Platform arms 31-33 are further lowered an amount approximately equal to the thickness of a doughnut as conveyor continues to advance and push a third trio of doughnuts into the guide tubes, and further lowered by the same amount as a fourth set of three doughnuts are pushed from plate 91 to fall into guide tubes 31-33. Because the platform arms are lowered approximately in accordance with nominal doughnut thickness each time a further set of doughnuts is spilled into the guide tubes, it will be seen that each doughnut falls approximately the same distance when it falls from plate 91, which simplifies the provision of an arrangement which will flip all of the doughnuts into the guide tubes in a uniform manner.

After four trios or one dozen doughnuts have been spilled into the guide tubes, so as to provide three stacks of doughnuts, each four doughnuts high, the platform arms 31-33 are lowered, through a greater distance, and preferably at a greater speed, until the arms lower through slots 41-43 in plate 40, leaving the three stacks of doughnuts standing on plate 40. Slots 41-43 in plate 40 are best seen in FIG. Ib, where the positions of their respective guide tubes mounted above them are shown in phantom. While the platform arms are lowered out of the bottoms of the guide tubes and down through slots 41-43 in plate 40, conveyor 20 does not advance to push any more doughnuts into the tops of the guide tubes. However, when the platform arms 31-33 have lowered just below plate 40, to the level where arm 32!) is shown in FIG. la, a new set of three platform arms will have entered the vertical slots in the guide tubes and will lie at the vertical position shown for arm 32a in FIG. la. A new machine cycle will then begin, and the process heretofore described will be repeated.

When three four-high stacks have been formed in the guide tubes, and after the platform arms upon which those stacks are resting have been lowered to place the stacks on plate 40, a box B is pushed into the position shown in FIGS. la and lb, by a pusher or conveyor means (not shown). While one set of three platform arms is situated within the guide tubes and being lowered and four doughnuts are being pushed successively into each guide tube, pusher plate 56 is reciprocated, being first advanced leftwardly from the position shown in FIG. la and then returned to the position shown, by means of crank arm 57 pivotally connected between plate 56 and drive wheel 58. The leftward travel of pusher plate 56 pushes the three stacks of doughnuts leftwardly on plate 4t), into box B shown supported on plate 40. The upper face of plate 40 under the box is preferably slightly lower than the face of plate 40 below the guide tubes, so that the stacks f doughnuts move slightly downwardly as they are pushed leftwardly, and so that the bottom doughnut in each stack does not catch on the edge of the lower side of the box. A pair of guide plates 61, 62 best seen in FIG. 1 converge toward the open side of the box, thereby guiding the three stacks of doughnuts into the box and lessening any tendency for any of the stacks to topple while it is being pushed into the box. A flange 64 extending upwardly from one edge of plate 40 prevents leftward movement (in FIG. la) of box B as the pusher plate pushes the three stacks of doughnuts into the box. Flange 64 is also slotted at three places (64a-c in FIG. lb) along its length to allow the platform arms to move downwardly through plate 40. After pusher plate 56 has been translated to fill box B, the box is moved from below the guide tubes,being translated downwardly as viewed in FIG; 1, by mechanism 92, which pushes the box from beneath the guide tubes onto plate 400. This mechanism then retracts and places another empty box into location when needed. A portion 400 of plate 40 is bent downwardly, to provide a tilted ramp, which slopes both downwardly and to the left as viewed in FIG. 1. As the filled box B is pushed downwardly and the center-of-gravity of the box passes over the edge of the tilted ramp 40c, the filled box not only slides down the tilted ramp, but also flips onto its bottom, so that the open side of the filled box is then up. A continuously running output conveyor located just below the exit end of the tilted ramp then conveys the filled and righted box to one or more futher stations (not shown), where the box is closed or covered and labelling added, etc.

A synchronizing unit shown as a box SU in FIGS. 1 and la and shown schematically in FIG. 2 drives conveyor 20, chains 51, 52 and pusher plate drive wheel 58 so as to provide the timing relationships described aove. The constant speed motor M drives a pair of cams C1 and C2 through a gear reduction RG-l, and is also connected to one side of clutches CL-l and CL-2, which are controlled by cams C1 and C2, respectively. During one portion of a machine cycle cam Cl operates clutch CL-l, the output shaft of which is connected (1) via gear reduction RG-2 to drive the platform arm drive chains via mechanical differential MD, (2) via gear reduction RG-3 to drive conveyor 20, and (3) via gear reduction RG4 to drive pusher plate drive wheel 58. During this portion of the machine cycle eonveyor 20 pushes twelve doughnuts into the three guide tubes, a trio of platform arms moves from near the top of the guide tubes to near the bottoms of the guide tubes, and pusher plate 56 reciprocates to push three previously formed stacks of doughnuts into a box. During a second portion of a machine cycle cam C] releases clutch CLJ and cam C2 engages clutch Clo-2. The engagement of clutch CL-Z applies an input to differential MD so as to lower the platform arms at an increased speed, and gear reduction RG-S operates the box pusher to displace the filled box with a new, empty box. Eventually ca'm C2 releases clutch CL-Z and cam Cl re-energages clutch CL-il to begin a further machine cycle.

In the modified arrangement partially illustrated in FIG. 3, the two drive chains which lower and raise the sets of platform arms are each reaved over more than two sprockets so as to provide a substantial horizontal space between the downward and upward courses of the chains. The boxes to be filled pass between the two courses, and the pusher plate pushes the stacks of doughnuts in between the two courses in order to place the stacks in the boxes. The stacks are formed in the same manner as in the previous embodiment, by pushing doughnuts into vertical guide tubes as platform arms similar to those of FIG. I are lowered through the guide tubes, and the stacks are then lowered to rest on plate 40' as the platform arms pass down through slots in plate 40'. Inasmuch as space for a box need not be provided between the chains and the area below the guide tubes, it will be seen that the cantilever platform arms in FIG. 3 may be considerably shorter than those used in the arrangement of FIG. 1.

Pusher plate 56' reciprocates generally similarly to plate 56 of FIG. 1, but reaches further, past the downward chain course. As pusher plate 56' approaches it leftmost excursion in FIG. 3, it preferably encounters a slight ramp, such as that shown at 40d, so that plate 56' moves slightly upwardly during the final portion of its leftward travel. When plate 56' has moved leftwardly far enough to insure that the doughnut stacks are fully installed in the box, a cam boss 58a carried on drive wheel 58 operates microswitch S-l, thereby energizing electromagnet coil EM. A magnetic core associated with electromagnet EM is attached to the end of crank arm 65, which extends from shaft 66, and energization of magnet EM pulls the magnetic core down inside the coil, thereby rotating shaft 66, against the force of a restoring spring (not shown). A sprocket on shaft 66 is connected by chain 67 to a sprocket on shaft 68, so that shaft 68 also rotates as electromagnet EM is energized. A plurality of fingers 69 extend radially from shaft 66, and prior to energization of the electromagnet, the fingers serve as stops which engage the upper (and leftward in FIG. 3) corner of the box. Shaft 68 also carries a plurality of radially extending fingers 70 which extend partially downwardly, at an angle such as that shown in FIG. 3, so that they do not cover or block any of the open side of the box. As switch S-l energizes electromagnet EM, the rotation of shaft 66 removes fingers 69 from the upper left edge of the then-filled box. Simultaneously, the clockwise (as viewed in FIG. 3) rotation of shaft 68 causes fingers 70 to sweep downwwardly and then upwardly, so that fingers 70 both raise and urge leftwardly the upper right edge of the box. The lower left edge of the box is engaged by slightly-raised flange 64' on plate 40'. It will be seen that fingers 70 (together with the slight upward motion of plate 56' if ramp 40d is provided) will rotate the box about its lower lefthand edge, toppling the box over flange 64, so that the box will fall and land in an upright position (i.e., with its open side up) on conveyor belt 72, which conveys the filled boxes to a box-closing machine (not shown).

FIGS. 4a and 4b illustrate several modifications which are generally applicable to the various embodiments of the invention. Rather than having a single vertical slot to permit the platforms to be lowered through them, the guide tubes 125-128 of FIGS. 4a and 4b have two slots which extend the complete length of each tube on opposite sides of the tube, so that each tube is formed by two separate pieces, which, of course, must be separately supported. Angle bracket 101 supports the leftward halves of guide tubes 125-128, while angle 1102 supports the rightward halves, the two angles extending completely across the machine to side walls (not shown). Horizontal bars 153a and 153k extend between chains and 152, and successive such bars are lowered through the guide tubes as sprockets 103, 104 drive the chains. Short fingers 154, 154 or widened portions of bars 153a etc., serve as platforms which are lowered through the guide tubes. An opening 141 in plate 140 allows each cross bar 153 and its associated finger to be lowered through plate 140. Secondly, rather than pushing the formed stacks beneath or inside the chain and cross bar mechanism, pusher plate 156 is arranged to push them in an opposite direction. Pusher plate 156 lies in the position shown in FIGS. 4a and 4b when a cross-bar lowers a plurality of stacks onto plate 1140. Thereafter, pusher plate 156 is pulled rightwardly by a pair of crank arms 157a and 15712 which engage plate 156 outside the ends of bars 153, so that the plate 156 pushes the stacks into box B. While" box B is being filled it rests on trapdoor 105, which is hinged at 106 to plate 140. After the box is filled, counterclockwise rotation of crank wheel 107 lowers trapdoor 105, to the position shown in dashed lines at As trapdoor 105 reaches a certain downward angle, the filled box trips over flange 105a, and lands bottom side down on conveyor 106. Crank wheel 107 then closes trapdoor 105 and a further box is pushed into place on the trapdoor.

It will become apparent at this point that the twosection guide tubes may be used in the previously described arrangements without using the trapdoor boxremoving arrangement, and vice versa. Furthermore, plate 156 could be pushed rightwardly by a crank wheel and. crank arm (not shown) located on the left side of the pusher plate, and then the box-removing technique of either FIG. 1 or FIG. 3 could be employed in FIG. 4.

It will be readily apparent that hydraulic or pneumatic cylinders, or motor-driven rack-pinion arrangements may be used in lieu of the crank arms shown connected to reciprocate the pusher plate.

While the invention is illustrated in connection with packing three stacks of doughnuts into a box, with four doughnuts in each stack, it wil be apparent at this point, that with obvious modifications, the machine could instead insert four stacks of doughnuts into a box, with three doughnuts on each stack. Furthermore, it is in no way necessary that a dozen articles be packed into a box, and in various applications of the invention the number of stacks formed and the number of articles in each stack may vary widely. It is not essential that tubular guide tubes 25-27 be precisely cylindrical (i.e., of constant diameter along their lengths), and in many applications it will be desirable that the upper ends of the tube be flared. In some applications of the invention the guide tubes may take the form of a truncated cone, having a diameter clearly larger than that of the articles to be stacked at the upper portions of the tubes, and a convergence to a lesser diameter near the bottoms of the tubes, so that all of the articles in a stack will be stacked accurately one atop another as they are lowered out of the bottom of the tube. Furthermore, it is not essential that the guide tubes be previously circular in cross-section for most applications of the invention.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:

I. The method of packing a plurality of generally cylindrical articles carried on a conveyor into a portable container comprising the steps of: expelling said articles in succession from said conveyor to allow said articles to fall by gravity into a hollow stack-forming guide means where said articles are successively stacked one atop of another; simultaneously lowering a platform means within said guide means so that successive ones of said articles fall substantially the same distance from said conveyor to their respective locations in the stack of articles in said guide means; further lowering said platform means with said stack of articles carried thereon until the entire stack of articles emerges below said guide means; and pushing said stack of articles generally horizontally into said container.

2. The method according to claim 1 in which said step of further lowering said platform means involves lowering said platform means through openings in a plate means, said openings being smaller than the plan view cross-sectional area of said stack, whereby the lowering of said stack is limited by said plate means and wherein said step of pushing comprises pushing said stack of articles with the bottom article in said stack resting on said plate means.

3. The method according to claim 1 wherein said step of expelling said articles comprises expelling groups of articles substantially simultaneously from said conveyor to allow each group to fall into a plurality of hollow stack-forming guides to provide a plurality of stacks of said articles; and wherein said step of pushing comprises pushing said plurality of stacks simultaneously into said container.

4. Apparatus for stacking a plurality of articles carried on a conveyor means, comprising, in combination: a vertically extending tubular guide means; platform means adapted to be lowered through said tubular guide means; first means situated a predetermined distance above said tubular guide means for expelling successive ones of said articles to allow said articles to fall into said tubular guide means; and platform translating means for lowering said platform means within said tubular guide means, whereby the first of a group of said articles falling into said guide means falls onto said platform means and successive articles of said group fall into said guide means to form a stack of said articles, said first means including a generally horizontal plate means having an edge and means for pushing each of said articles towardsaid edge, said tubular guide means being located sufficiently below and beyond said edge that each of said articles may fall and land inverted as it is pushed off the edge of said plate means and falls to its respective position in said stack.

5. Apparatus according to claim 4 having a generally vertical pusher plate means; second means for reciprocating said pusher plate means generally horizontally across said horizontal plate means beneath said tubular guide means, and means for synchronizing the operation of said second means with said platform translating means.

6. Apparatus according to claim 5 wherein said platfonn translating means comprises an endless chain means having upward and downward courses, said apparatus including means for supporting a container in between the upward and downward courses of said endless chain means.

7. Apparatus according to claim 5 having means for supporting a container on said horizontal plate means at a horizontal position displaced from beneath said tubular guide means, whereby reciprocation of said pusher plate means pushes said stack of articles into said container.

8. Apparatus according to claim 7 having means synchronized with said pusher plate means for displacing said container from said horizontal plate means and for rotating said container after said stack of articles has been pushed into said container.

9. Apparatus according to claim 7 having conveyor means, chute means extending between said container supporting means and said conveyor, and means for pushing said container onto said chute means, said chute means sloping in two different directions along its length, whereby said container is rotated as it descends along said chute means.

10. Apparatus'according to claim 7 wherein said means for supporting a container comprises trap door means mounted on said horizontal plate means. 

1. The method of packing a plurality of generally cylindrical articles carried on a conveyor into a portable container comprising the steps of: expelling said articles in succession from said conveyor to allow said articles to fall by gravity into a hollow stack-forming guide means where said articles are successively stacked one atop of another; simultaneously lowering a platform means within said guide means so that successive ones of said articles fall substantially the same distance from said conveyor to their respective locations in the stack of articles in said guide means; further lowering said platform means with said stack of articles carried thereon until the entire stack of articles emerges below said guide means; and pushing said stack of articles generally horizontally into said container.
 2. The method according to claim 1 in which said step of further lowering said platform means involves lowering said platform means through openings in a plate means, said openings being smaller than the plan view cross-sectional area of said stack, whereby the lowering of said stack is limited by said plate means and wherein said step of pushing comprises pushing said stack of articles with the bottom article in said stack resting on said plate means.
 3. The method according to claim 1 wherein said step of expelling said articles comprises expelling groups of articles substantially simultaneously from said conveyor to allow each group to fall into a plurality of hollow stack-forming guides to provide a plurality of stacks of said articles; and wherein said step of pushing comprises pushing said plurality of stacks simultaneously into said container.
 4. Apparatus for stacking a plurality of articles carried on a conveyor means, comprising, in combination: a vertically extending tubular guide means; platform means adapted to be lowered through said tubular guide means; first means situated a predetermined distance abovE said tubular guide means for expelling successive ones of said articles to allow said articles to fall into said tubular guide means; and platform translating means for lowering said platform means within said tubular guide means, whereby the first of a group of said articles falling into said guide means falls onto said platform means and successive articles of said group fall into said guide means to form a stack of said articles, said first means including a generally horizontal plate means having an edge and means for pushing each of said articles toward said edge, said tubular guide means being located sufficiently below and beyond said edge that each of said articles may fall and land inverted as it is pushed off the edge of said plate means and falls to its respective position in said stack.
 5. Apparatus according to claim 4 having a generally vertical pusher plate means; second means for reciprocating said pusher plate means generally horizontally across said horizontal plate means beneath said tubular guide means, and means for synchronizing the operation of said second means with said platform translating means.
 6. Apparatus according to claim 5 wherein said platform translating means comprises an endless chain means having upward and downward courses, said apparatus including means for supporting a container in between the upward and downward courses of said endless chain means.
 7. Apparatus according to claim 5 having means for supporting a container on said horizontal plate means at a horizontal position displaced from beneath said tubular guide means, whereby reciprocation of said pusher plate means pushes said stack of articles into said container.
 8. Apparatus according to claim 7 having means synchronized with said pusher plate means for displacing said container from said horizontal plate means and for rotating said container after said stack of articles has been pushed into said container.
 9. Apparatus according to claim 7 having conveyor means, chute means extending between said container supporting means and said conveyor, and means for pushing said container onto said chute means, said chute means sloping in two different directions along its length, whereby said container is rotated as it descends along said chute means.
 10. Apparatus according to claim 7 wherein said means for supporting a container comprises trap door means mounted on said horizontal plate means. 